<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>ES7</title>
</head>

<body>
    <script>
   
     alert(3**5)

     let arr = [2,7,4,5,3];
     alert(arr.includes(3));

    </script>
    <!-- 
      ES7,幂操作(求次方)
       ** 两个*等于     alert(3**5) 等于 Math.pow(3,5)
      Array.includes()  检查是否存在

     -->
</body>

</html>